1. Field of the Invention
The present invention relates to an image processing apparatus and method and, more particularly, to an image processing apparatus and method for processing an image sent from an external apparatus such as a host computer or the like, and an image read from an original.
2. Description of the Related Art
An image forming system which is constructed by a controller for receiving image data from a host computer and sending the received image data to an image forming apparatus, and an image forming apparatus for forming an image on the basis of the image data sent from the controller is known. For example, an image forming system as combination of a CLC500 (tradename) color copying machine as an image forming apparatus and various controllers is commercially available. This color copying machine is a laser beam type color electrophotographic printer which frame-sequentially forms images in correspondence with a plurality of output color components C (Cyan), M (Magenta), Y (Yellow), and K (Black), and realizes halftone expression by controlling laser beam emission by a signal pulse-width-modulated in accordance with an image signal.
In such image forming apparatus, a technique for stabilizing the quality of an output image via density correction and gradation correction by forming a predetermined pattern on an image carrier or recording medium, and reading the density of the formed predetermined pattern is known.
However, the aforementioned technique suffers the following problems.
An image output by reading an original image by the color copying machine alone as the image forming apparatus (to be referred to as a xe2x80x9ccopy imagexe2x80x9d hereinafter), and an image output based on image data sent from the controller (to be referred to as a xe2x80x9cprint imagexe2x80x9d hereinafter) are not yet sufficiently standardized in terms of their density and gradation reproducibility.
A calibration system which adjusts the density and gradation reproducibility of a print image using an expensive densitometer is known. However, calibration that uses a reader/scanner of the color copying machine is not performed.
Furthermore, calibration that takes a color sample used as a standard into consideration is made, but no image adjustment corresponding to the color sample is made.
On the other hand, variations of the image density and gradation reproducibility include a short-term variation resulting from a variation of the apparatus environments, a long-term variation resulting from aging of a photosensitive body and toner, and the like. In order to standardize the density and gradation reproducibility of a copy image and print image, such variations must be corrected together.
The present invention has been made to solve the above-mentioned problems, and has as its object to provide an image processing apparatus and method, which can correct short- and long-term variations of the image density and gradation reproducibility by a standardized scheme upon formation of a copy image by the operation of the image forming apparatus alone, and upon formation of a print image based on image data sent from an external apparatus.
It is another object of the present invention to provide an image processing apparatus and method, which can perform image adjustment suitable for the image forming system with low cost using an image reading means of the image forming apparatus.
It is still another object of the present invention to provide an image processing apparatus and method which can perform image adjustment suitable for the image forming apparatus connected.
It is still another object of the present invention to provide an image processing apparatus and method which can perform image adjustment corresponding to a color sample.
To achieve the above object, according to one aspect of the present invention, there is provided to an image processing apparatus connected to a color-copy machine having calibration processing modes for a color-copy process and a color-print process, said apparatus comprising output means for outputting a command which indicates execution of calibration processing to said color-copy machine.
To achieve the above object, according to another aspect of the present invention, there is provided to an image processing apparatus which has an image reader generating a first image signal from an original, an generating unit generating a second image signal from image data described by page description language, and a printer forming a visible image on a recording medium based on the first or second image signal, said apparatus comprising first coordinating means for coordinating the visible image formed from the second image signal, using said image reader, and second coordinating means for subjecting image coordinating process to the second image signal using a conversion table which has a predetermined characteristic.
To achieve the above object, according to another aspect of the present invention, there is provided to an image processing apparatus comprising an image reader generates a first image signal form an original, generating means for generating a second image signal from image data described by page description language, correcting means for correcting the first or second image signal, a printer forms a visible image on a recording medium based on the corrected image signal, first setting means for, in image forming process based on the first image signal, setting correcting process of said correcting means and an image forming condition of said printer on the basis of an image signal generated by a pattern generator, and second setting means for, in image forming process based on the second image signal, setting the correcting process and the image forming condition on the basis of an image signal generated from image data described by the page description language.